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The Utility Interconnection Process - How Your Solar Panels Get Connected to the Grid

Utility inspector in yellow hard hat, yellow vest, and red-and-blue plaid shirt inspects a home solar panel installation with the words "Solar Interconnection" on top, as a homeowner applies for Permission To Operate.
PublishedMay 16, 2022
UpdatedMay 17, 2024
AuthorCory O'Brien HeadshotCory O'BrienSenior Director - Growth MarketingEditorRyan Barnett HeadshotRyan BarnettSVP, Policy & New Market Development
In this article
What Is Interconnection?
What Happens During The Interconnection Process?
The Importance of Interconnection
The Palmetto Difference - Regional Interconnection Teams
Interconnection Is An Essential Part Of The Overall Solar Process

Getting solar installed on your roof and generating clean energy involves many steps. Since most solar-powered homes remain connected to the electric grid, which is the distribution system that connects power plants with homes and buildings to provide electricity, one of the most important parts of this process is getting permission from the grid operator to connect your home to the grid.

This article will help you understand solar interconnection, so you know what needs to happen between your local utility company and your solar company before your solar system is authorized to start producing power.

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What Is Interconnection?

Interconnection is the process by which a solar customer applies for and receives permission from their local utility company to connect to the utility grid.

If you’re working with a professional solar company like Palmetto, they will likely take care of the interconnection process on your behalf. That said, it’s still helpful to understand what’s happening during this step in the solar installation process.

Timeline and Cost

The interconnection process for residential solar can take anywhere from two to four weeks on average, depending on your utility company and system size.

The cost for interconnection can depend on your utility, your home’s location in relation to the electric grid, and your solar system size. For most homeowners, this ranges from no cost to a couple of hundred dollars, and it will be included in the total cost of your system.

What Happens During The Interconnection Process?

Receiving approval from your utility provider is required to connect your solar power system to the utility grid so your solar panels can start generating electricity for your home. Most commonly, the solar interconnection process is separated into two key processes: permission to install, and permission to operate. However, some utilities only require a request for permission to operate and do not require permission to install.

While the specific steps may vary by utility company, the overall goal is the same: Ensuring that your solar energy system is properly designed and installed, so it’s safe for both your home and the electrical grid.

At the same time, any Authority Having Jurisdiction (AHJ - the local building department that controls your area) must approve significant construction projects, including solar energy system installations. Therefore, we apply for permits to obtain that approval while also pursuing interconnection to help speed up the timeline. You can read more about this process at How Local Solar Permitting Impacts the Cost of Your Solar Panels.

Part One: Before The Installation (Permission To Install)

If your utility requires you to request permission to install as part of the interconnection process, your solar company will submit an application to your utility provider to review the electrical plans, equipment specifications, and overall system design. Their goal is to ensure the electrical equipment meets all applicable standards for interconnection.

Steps for Conditional Interconnection Approval

  1. Your solar company submits an interconnection application to your utility company for permission to install, which may include:
    1. Your signature as the utility account holder on all relevant documentation
    2. The engineering plan set for your solar power system
    3. Homeowners’ insurance, supplemental documentation, and additional engineering documentation may also be required, depending upon local requirements
  2. The utility company reviews the application for accuracy and adherence to interconnection standards.
  3. The utility company verifies grid capacity is available and confirms that all engineering specifications meet utility standards.
  4. If all requirements are met and grid capacity is confirmed, the utility will issue approval to install.

Between steps 2 and 4, the application can be kicked back by the utility company. If this happens, your solar contractor must make corrections or provide additional information before approval can be granted.

See how much you can save by going solar with Palmetto

Step 01
Step 02
My electric bill is $290/mo

Part Two: After The Inspection (Permission To Operate)

After your system has been installed and passed all required local jurisdiction inspections, your solar contractor will begin Part Two of the interconnection process, often referred to as submitting Permission to Operate or PTO. While Part One requires a review of the installation plans, Part Two requires a review of the completed installation.

Steps for Permission to Operate

  1. Your solar company submits a ‘Part 2’ interconnection application to your utility company for permission to operate, and it may include:
    1. Installation photos
    2. Passed inspection documentation
    3. Part Two Interconnection documentation
    4. Your signature on relevant documentation
    5. Any additional supplemental information your specific utility may require
  2. The utility company reviews your solar power system, checking for any issues. Some utilities send their staff to your home for an on-site inspection, while others may approve virtually based on installation photos. If the solar equipment is located outside, you may not need to be home during this step, but if the inverter or AC disconnect is in the garage, you will likely need to be home to allow utility staff access.
  3. If the installation does not meet utility requirements, the solar contractor will make adjustments and then re-apply for PTO.
  4. During the installation process, the utility will ‘reset’ or ‘swap’ your electric meter to a bi-directional meter that can accurately measure kilowatt-hours (kWh) flowing from the grid to your home, and excess solar energy production your home does not use that flows to the grid.
  5. Once your solar energy system receives permission to operate, you can activate your system and begin generating electricity.

Common reasons that PTO for your solar energy system might be rejected include:

  1. The inspector needs to clear the work order by calling the utility to confirm the inspection was passed.
  2. The customer’s utility company account has issues or has a hold.
  3. The system failed the utility company’s inspection.

The Importance of Interconnection

Clear and defined interconnection processes are essential for public safety. Utility companies need to review each and every interconnection to the grid so that people, property, and systems are kept safe and secure.

Solar power systems that are connected to the grid are designed to shut down automatically during power outages to ensure solar electricity does not harm utility workers. Solar power systems with battery storage are designed to continue producing solar electricity while ensuring that all excess production is stored in the battery and not sent to the grid during power outages. (This is known as solar islanding.)

The interconnection process is the utility’s chance to verify that the safety measures necessary to connect your solar power system with the grid are in place and working, and also set your electric bill up for net metering if available.

It’s important to understand that utility processes and requirements can change. Such updates can be based on grid capacity to accept further renewable energy systems, changes to regulations around accepted solar equipment, changes to utility's internal processes, and changes to state-level interconnection standards. Your solar company should employ interconnection specialists who stay up to date with current processes for every utility company they work with. This will help ensure that the interconnection process moves as smoothly and safely as possible.

The Palmetto Difference - Regional Interconnection Teams

At Palmetto, we know that processes, timelines, and requirements will vary by utility company. That’s why we have standardized internal processes and regional interconnection teams that maintain current and accurate information about the utility companies in their assigned service area.

By approaching utility companies with professionalism and respect, we can improve communication and help keep your solar project on track.

Interconnection Is An Essential Part Of The Overall Solar Process

It’s important to have both your planned installation and your completed installation reviewed so everyone is kept safe when connecting your system to the utility grid.

While it can be a lengthy process, an experienced solar company like Palmetto can ensure your interconnection moves smoothly and safely.

If you want to learn more about getting solar panels installed on your home, talk to Palmetto today! You can get started with our Free Solar Design Tool to see how solar panels might look on your roof and how much you could save.

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My electric bill is $290/mo
About the AuthorCory O'Brien HeadshotCory O'BrienSenior Director - Growth Marketing

Cory brings over 8 years of solar expertise to Palmetto, and enjoys sharing that knowledge with others looking to improve their carbon footprint. A dog lover residing in Asheville, NC with his wife, Cory graduated from UCSB. If you run into him, ask him about the company he founded to rate and review beer!

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